The Best Cable Modem

If you have cable Internet, you already have a cable modem, and you’re probably paying your Internet service provider a separate fee every month to rent it. Stop giving away your money. If you instead buy a cable modem like the Netgear CM500, you can recoup its cost in as little as six months—and then start saving up to $10 each month.

Last Updated:
One month ago

After a new round of research, the Netgear CM500 is our new pick for most people because it's compatible with the most major cable ISPs, it’s popular and reliable, and it tends to be less expensive than similar options. If that's out of stock, get our new runner-up, the TP-Link TC-7620.

Two months ago:
After a new round of research, we’ve decided that the Netgear CM500 is our pick for most people. This popular and reliable model is compatible with most major cable ISPs, and it tends to be less expensive than similar options. If that model is out of stock, get our new runner-up, the TP-Link TC-7620. If you have an Internet plan that is faster than 300 Mbps but isn’t a DOCSIS 3.1 gigabit plan, we have a new upgrade pick for you: the Arris SURFboard 6190. Stay tuned for the full update.

11 months ago:
Our old pick, the Arris SB6141, is still a good cable modem—if you have it, there’s no reason to upgrade. But we’re switching our rec to the Arris SB6183, which supports twice the maximum download speeds and doesn’t have the compatibility issues many Comcast customers reported.

One year ago:

The Arris SURFboard SB6141 is vulnerable to attacks that could trick you into rebooting your cable modem, causing you to lose Internet access for a few minutes. While the situation isn’t dangerous, it is annoying. To prevent such attacks, go to your router’s URL filter or IP Table settings and block access to 192.168.100.1. For more information, see our Care, maintenance, and setup section below.

Two years ago:
We’ve added a number of new cable modems to our Competition section. If you don’t need a cable modem that works with multiple ISPs, you might be able to find one that’s as good as our pick for even less.

Two years ago:
We've been hearing a number of reports that Comcast has moved our pick, the SURFboard SB6141, to end-of-life status. The leased version has; the retail version (our pick) hasn't. We spoke to our contacts at Comcast HQ, and here's what they told us:
"...[W]e recently moved the SB6141 to end of life status for customers who have been leasing that particular modem from us. We will be swapping that device with newer models for no additional charge (for leased customers) as needed. For customers who have either already purchased the SB6141 or are considering buying one, we continue to support the device and we’re working with the manufacturer to ensure it continues to receive regular firmware updates that keep it running well. However, if they are unable to continue to provide regular firmware updates (such as bug fixes), then we may also consider moving the retail version to end of life status as well."

Three years ago:
After another 14 hours of research, our favorite cable modem from last year is still the best option if you're looking to save money on a rental fee. The $90 SURFboard SB6141 is compatible with almost all of the fastest Internet plans from seven of the eight biggest providers. Other modems support as many providers, but none support most of their fastest speeds.

Three years ago:
Many cable modems, including the SB6141, are vulnerable to cross-site scripting attacks; an attacker can trick people on your network into running code that factory resets your modem. To prevent this, use your router's built-in firewall to block the modem's local IP address. For Motorola modems, it's 192.168.100.1. And change your router's administrator password from the default if you haven't already; this prevents a similar attack from taking control of your router.

Five years ago:
It was pointed out that Comcast's modem list shows the SB6141 does not support IPv6. However, this list seems to be inaccurate; Motorola's website says the SB6141 does support IPv6 and we stand by our pick.

After researching nearly 100 cable modems over the past four years, we recommend the Netgear CM500 for most people. The CM500 offers reliable operation, supports the Internet speeds available to most Americans, and has positive reviews from owners. Just as important, it’s compatible with the most major cable Internet service providers in the US—including Comcast, Spectrum (formerly Time Warner, Charter, and Bright House), Cox, Suddenlink, Cable One, and WOW—which gives you the flexibility to switch providers if you move (or if you’re lucky enough to have multiple ISPs to choose from).

The CM500 works well for plans up to 300 megabits per second, because it’s a DOCSIS 3.0 modem that can handle 16 downstream channels and four upstream channels. (A channel is a connection to your ISP, like a lane on a road. The more channels you have, the easier it is to avoid congested traffic. While channel availability varies by region, 16×4 is the maximum you need for the most common current plans.) The CM500 has a good reputation for reliability, but it comes with only a one-year warranty, while most modems come with a two-year warranty.

The TC-7620 is as compatible and as capable as the CM500 and comes with a longer warranty, but it can be more expensive.

If the CM500 is out of stock, get the TP-Link TC–7620. It has just as much ISP support, and it should work on most plans that top out at speeds of 300 Mbps. The TC-7620 doesn’t have a large pool of reviews, but the ones it does have are generally positive. TP-Link is also a reputable company, and it provides a two-year warranty on the TC-7620. While the TC-7620 was more expensive than the CM500 at the time we conducted our research, it’s an equally good option that comes with a better warranty.

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Table of contents

Why you should trust us

Before joining The Wirecutter, Thorin Klosowski spent almost six years at Lifehacker writing about hardware, software, and every other facet of technology. Patrick Austin has spent four years covering consumer technology and news for sites like Ars Technica, Consumer Reports, and PCMag, and was the technology editor for business magazine Black Enterprise. David Murphy spent two years as The Wirecutter’s networking expert, and he tested everything from computer cases to network-attached storage in his decade-plus career as a tech journalist before that.

Who this is for

You should buy a cable modem if you’re currently paying a fee to rent one from your ISP. Most ISPs charge $10 a month to rent a modem—that’s $120 a year, every year, on top of what you’re already paying for Internet access. (Spectrum includes the modem-rental cost in its current Internet plans, but if you haven’t changed your plan since the Time Warner–Charter merger in 2016, you may still be paying a rental fee; give Spectrum a call to see what your current options are.) Unless you have gigabit-speed Internet, you can expect to pay around $60 to $80 for a modem, which means you’ll save money in less than a year.

Many ISPs rent out modems that double as wireless routers, which means that if you want to buy a cable modem, you may also need to buy a wireless router if you want Wi-Fi in your house. Our favorite Wi-Fi router sells for around $100, which puts your total up-front cost at about $170. Your modem and router should last you at least a few years if not more, so you’ll still come out on top if you buy your own.

Monthly modem-rental fees (as of August 2017)

ISP

Monthly fee

Comcast

$10

Spectrum

$10 or no charge

Cox

$10

Optimum

$10

Suddenlink

$10

WOW

$10

(Legacy plans from Time Warner Cable or Charter may include a modem-rental fee depending on who your ISP was before the merger. Most current Spectrum plans do not have a separate modem-rental fee.)

Don’t buy a cable modem if you’re on DSL or fiber; those technologies use different standards and connectors. Also don’t buy one if you use your cable provider for telephone service: The models we cover here don’t have phone ports. If you need one that does, check to see which “telephony” or eMTA modems your ISP supports, and if the company allows you to buy your own. Telephony modems are more expensive than regular cable modems.

You should get a new modem if yours doesn’t support DOCSIS 3.0, the most widespread iteration of the Data Over Cable Service Interface Specification, which governs how cable operators deliver high-speed cable Internet. Every revision to DOCSIS has improved performance and added new features. If you’ve had your modem for four or five years, give the model name a quick Google search; you might still be using a modem that supports only DOCSIS 2.0, in which case it’s time to upgrade.

The first two versions of DOCSIS used only one downstream channel (for downloading data) and one upstream channel (for uploading data). The jump from 1.0 to 2.0 made upstream traffic faster, but modems still used a single channel for each direction, topping out at 43 megabits per second down and 31 Mbps up. DOCSIS 3.0 allows modems to bond multiple channels into a single data stream, giving you 38 Mbps per channel. Since those channels can combine, you get up to 606 Mbps with a 16-channel modem and up to 1.2 gigabits per second with a 32-channel modem—much faster.

DOCSIS 3.1 enables speeds over 1 Gbps. DOCSIS 3.1 is available in a few cities right now and is rolling out further over the next few years, though only a handful of compatible modems are available currently. You’ll need a DOCSIS 3.1 modem only if you’re in one of those cities and you have a gigabit-speed Internet plan—they’re expensive right now, and you won’t see faster speeds unless you pay for one of those gigabit plans.

If you already own a DOCSIS 3.0 cable modem that supports your Internet plan’s top rates, don’t buy a more powerful (and more expensive) cable modem for the sake of future-proofing. Wait until you decide to upgrade your plan, or your ISP increases your speed for free (which can happen). That way, you’ll be sure to get the best option at that time. Some newer modems support 24 or 32 downstream channels, which could improve the reliability of your connection, but your ISP has to provide those channels for you to get better speeds, and ISPs rarely share channel-bonding information with the public.1 Unless you’re on a very congested network with constant slowdowns, you likely won’t notice a huge difference from added channels on slower speed tiers.

DOCSIS 3.1 will be rolling out broadly over the next few years. Cox aims to introduce DOCSIS 3.1 by 2020, and the regional provider Mediacom has already rolled it out in parts of Indiana. Nationally, Comcast intends to deploy its speedier DOCSIS 3.1 Internet plans in 15 cities by the end of 2017 and 39 cities by the end of 2018. If you are in one of those cities and want to subscribe to one of the proposed gigabit Internet plans, wait to purchase a modem until you have the plan so that you know it’s compatible. DOCSIS 3.1 modems are pricey right now—around $170—and they could be much cheaper by the time you get DOCSIS 3.1. Right now, a DOCSIS 3.1 modem offers a more reliable connection to your ISP, but the minuscule benefit doesn’t outweigh the excessive cost for anyone on a slower-than-gigabit Internet connection. DOCSIS 3.1 is also completely backward compatible, so if you have a DOCSIS 3.0 modem and don’t plan on upgrading to gigabit speeds, the DOCSIS 3.0 modem will continue to work with your ISP.

Regardless of which modem you choose, you’ll need to activate it once you get it. Each ISP has a different activation process, but you’ll need to either call the company or visit a URL to activate your modem. Here’s how to activate your new modem on Comcast, Spectrum, Cox, Suddenlink, and Cable One. You’ll need to call WOW’s customer service line to activate your modem with that ISP.

How we picked

Nobody really reviews cable modems—it’s difficult, because you can’t know whether it’s the modem or the ISP that’s to blame for slower speeds—so the few reviews that exist aren’t very scientific. We also don’t have the capability to test multiple modems on multiple ISPs ourselves. But generally speaking, modems either work or don’t.

Instead, we started our research by considering all the DOCSIS 3.0 modems that work on the nation’s biggest ISPs—Comcast, Spectrum, Cox, Optimum (owned by Cablevision), Suddenlink, Cable One, and WOW—and then narrowed the field to modems compatible with the most popular plans on those ISPs. (Optimum doesn’t publish a list of approved modems, though, and wouldn’t verify whether any of our picks would work with its service.) The average Internet speed in the US is around 55 Mbps, and the fastest cable tier most major ISPs offer is between 100 and 300 Mbps. Our top picks will work for any plan below 300 Mbps. (A few ISPs offer faster plans, but those still have limited availability and many don’t use DOCSIS 3.0 modems.) We found that you should expect to pay $60 to $80 for a modem that works with most plans and has the features you need to get the highest speeds available to you:

Compatibility: ISP compatibility is the main factor in choosing a cable modem. A modem either works with your ISP or doesn’t. The first thing to do is to check your ISP’s approved-modem list—here’s where to check for Comcast, Spectrum, Cox, Suddenlink, Cable One, and WOW (PDF). If you’re lucky enough to live in a city where you can choose from multiple ISPs, the capability to bring your modem from one provider to another is a nice bonus.

Channels: Channel bonding refers to the number of downstream (for downloading) and upstream (for uploading) channels your modem can access. Modem channels appear on the box as a number, such as 16×4 or 32×8. With DOCSIS 3.0, the more channels your modem has, the faster the speed, provided your ISP supports those channels. This means that if the ISP offers only 16 downstream channels in your area, using a 32×8 modem won’t improve performance. The right cable modem is the one with the right number of channels for your service tier. If you have service ranging from 100 to 499 Mbps, a 16×4 modem will be enough. If your Internet plan is over 500 Mbps, you need a 32×8 modem.

We don’t recommend 8×4 or 4×4 modems, because ISPs are phasing out support for those older models, even on lower-speed plans. For example, we’ve seen Comcast customer reports claiming that Comcast no longer supports one of our older picks, the Arris SURFboard SB6141, even though it’s on the company’s official compatibility list. Similarly, WOW recently cut off support for our previous pick, the Arris SURFboard SB6183. These types of support issues make it hard to recommend an older 8×4 or 4×4 modem even if it might shave $10 to $20 off the price.

Warranty: Most modems come with a one- or two-year limited warranty that covers any catastrophic failure. A warranty is useful, because a company will typically replace a modem if it stops working due to defects. Malfunctions are not a common occurrence with modems, but since purchasing your own means you don’t get a warranty through your cable provider anymore, the warranty is good to have in case anything goes wrong.

Heat: Read the owner reviews for almost any modem, and someone will mention that the modem gets hot. Most manufacturers list the operating temperature on modems as up to 104 degrees Fahrenheit, which is pretty hot for any electronic device. To keep your modem from overheating, make sure the vents aren’t covered up and it’s in an open space. Modems might be a bit ugly, but that doesn’t mean you should hide yours away in a drawer.

We also identified a few features that aren’t particularly useful for most people:

Modem-and-router combos aren’t a good idea for most people. As CNET’s Dong Ngo explained in a previous version of a cable modem shopping guide: “First, it’s risky. If either the modem or the router portion is broken or becomes obsolete, you have to replace the entire thing. The second reason is that, in most existing combo devices, the router is generally very limited, making your home network a lot less capable and flexible than it could be.”

A modem’s maximum speed, as the manufacturer lists it, doesn’t mean all that much. If a modem is capable of hitting 686 Mbps, that doesn’t mean an ISP has provisioned it to do so. For example, most ISPs limit 16×4 modems to around 300 Mbps. Most currently available 24×8 or 32×8 modems max out at 500 Mbps or 1 Gbps, respectively. If you buy a 1 Gbps modem but pay for only 300 Mbps service, your download speeds are still limited to 300 Mbps.

Future-proofing is good in theory but difficult in practice. It might sound smart to buy the best modem available, but the interplay between the technology, your location, and the ISP means your chances of wasting money on a device that might not work in the future are higher with modems than with other types of electronics. Internet providers tend to be coy with their technology and service rollouts, so it’s difficult to tell when—or if—you’ll see a bump in the speeds they offer. For example, just because some parts of Denver have access to gigabit speeds doesn’t mean the surrounding suburbs will. A few oddball DOCSIS 3.0, 32×8 modems, like the Arris SURFBoard SB6190, offer the promise of gigabit speeds and might be appealing to future-proofers, but very few ISPs support those modems at that speed tier. As Ars Technica writes, and as a DOCSIS representative we spoke with suggested to us, it’s in an ISP’s best interests to roll out DOCSIS 3.1 instead of utilizing the older technology’s higher speeds.

Our pick: Netgear CM500

Compatible with the most ISPs, the CM500 supports Internet plans up to 300 Mbps. It’s reliable, and it pays for itself in about six months.

The Netgear CM500 is a reliable 16×4 cable modem that works with all the major ISPs at the time of this writing. It works with the most commonly offered speed plans from Comcast, Spectrum, Cox, Suddenlink, and Cable One, as well as with WOW’s 100 Mbps plan. The Netgear CM500’s user manual (PDF) claims compatibility with Optimum, but if you have Optimum service, you should call your local Optimum customer support number to check before you buy any modem. And owners like it, too; Amazon reviews are consistently positive. At the time of our research, the CM500 was less expensive than the next-best option, the TP-Link TC-7620, but prices fluctuate, so we recommend buying whichever one is cheaper. Netgear told us this modem is sold as the Netgear CM500-1AZNAS in Amazon’s frustration-free packaging, but it’s the same modem you’ll find at other retailers such as Walmart.

The CM500 is a DOCSIS 3.0 modem with 16 downstream channels and four upstream channels. This is plenty for most Internet plans, which top out at 300 Mbps, and many ISPs require a 16×4 modem for their top non-gigabit plans, such as Comcast’s Extreme 250 plan or Cox’s Internet Ultimate plan. Even though DOCSIS 3.1 has begun rolling out, that standard is backward compatible, so all DOCSIS 3.0 modems will work with DOCSIS 3.1 service.

While the CM500 has solid support from every major ISP right now, double-checking your ISP’s compatibility page before you purchase the modem is still a good idea. ISPs update their modem-compatibility lists often, and they occasionally drop support for a modem with little to no warning. That’s what happened when WOW dropped our previous pick, the Arris SURFboard SB6183. That change, combined with the SB6183’s complications with IPv6 on Spectrum, prompted us to turn to the CM500 as the better choice. The SB6183 is still wildly popular, though, and if you already have the SB6183 (or even the older SB6141) and it’s working fine for you, stick with it—you have no reason to switch over to the Netgear CM500.

Flaws but not dealbreakers

While reviews suggest that the CM500 is a reliable modem, Netgear’s included one-year warranty isn’t great considering most other modems come with a two-year warranty. Modems tend to run pretty hot—the maximum operating temperature for the CM500 is 104 degrees Fahrenheit (PDF)—so there’s always a possibility of something going wrong if, for example, you don’t place yours in a well-ventilated area. That said, we think the popularity and the consistently lower price of the CM500, compared with our runner-up, outweigh its lackluster warranty.

Runner-up: TP-Link TC-7620

The TP-Link TC-7620 is just as good as the CM500, but it can be a bit pricier. Photo: TP-Link

The TC-7620 is as compatible and as capable as the CM500 and comes with a longer warranty, but it can be more expensive.

The TP-Link TC-7620 is just as good as our main pick and is the modem to buy if you can’t get the Netgear CM500, if the TC-7620 is cheaper, or if your ISP doesn’t support the Netgear. It matches the CM500 in compatibility and speed. The TC-7620 has positive reviews on Amazon right now, with 4.4 stars out of five overall, but that’s across only 317 reviews. While it has fewer reviews, the TC-7620’s reported reliability is in line with the CM500’s, and TP-Link’s two-year warranty is better than Netgear’s.

The TC-7620 is a DOCSIS 3.0 16×4 modem and works with all the same ISPs as the CM500. It’s not on Suddenlink’s compatibility list, but the company’s customer support department assured us that it (or any DOCSIS 3.0 modem, for that matter) works. If you’re a Suddenlink customer and you’re considering the TC-7620, it’s still a good idea to give Suddenlink a call to confirm before you purchase it.

What about DOCSIS 3.1?

DOCSIS 3.1 is the next standard for Internet cable modems and ISPs. It promises speeds of up to 10 Gbps, increased download efficiency, and better queue management for large downloads. The people behind DOCSIS suggest that the improved technology of the 3.1 standard will lead to better stability even at slower speeds. We spoke with Belal Hamzeh, vice president of wireless technologies at CableLabs, the company that came up with DOCSIS, and he pointed out that a big strength of DOCSIS 3.1 lies in the upgrade process: To introduce DOCSIS 3.1, an ISP doesn’t need to upgrade its cable lines—only the hardware in its facilities. This means that more cable operators will be able to offer gigabit speeds over the next few years. It also suggests that many ISPs may move to DOCSIS 3.1 instead of upgrading DOCSIS 3.0 systems to 3.0’s top speed of 1 Gbps. In doing so, an ISP will be able to offer higher speed tiers while retaining backward compatibility with DOCSIS 3.0 modems for slower speeds.

Right now, gigabit speed is possible on DOCSIS 3.0. Cable One is the only major ISP that widely supports it, and Suddenlink offers it in a few select cities. Gigabit DOCSIS 3.0 is also available in a few cities from regional cable carriers, but it’s not common. Gigabit fiber Internet plans are growing more popular, too—Suddenlink’s parent company, Altice, will be skipping DOCSIS 3.1 completely in favor of fiber.

Comcast, Cox, and WOW have announced or already rolled out DOCSIS 3.1 in some cities. Comcast’s plan is probably the most transparent of the bunch, but it’s still limited to a small number of cities. If DOCSIS 3.1 is available to you and you’re interested in a gigabit modem, you have only three options to choose from: the Netgear CM1000, Motorola MB8600, and Arris SURFboard SB8200. We recommend getting whichever modem works with your plan. If you have multiple options, choose whichever one is cheapest. Since these modems typically cost around $170, it takes longer to recoup the value on them, so depending on your situation, it might be best to rent your modem. All three are made by reliable companies, though like our top pick, the Netgear CM1000 has a shorter, one-year warranty versus the two-year warranties of the Motorola and Arris models.

What to look forward to

If you’re excited about the idea of 1 Gbps and higher download speeds, you’ll definitely want to keep an eye on DOCSIS 3.1. Even people who don’t mind a slower Internet connection might benefit from the rollout: One study (PDF) from the economic and strategy consulting company Analysis Group found that after ISPs introduced gigabit plans in an area, prices for plans of at least 100 Mbps dropped an average of $27 per month.

As DOCSIS 3.1 rolls out across the US, more people will have access to gigabit speeds that require new DOCSIS 3.1 modems. We expect to see the prices of those modems drop as the higher speed tiers spread.

Cable isn’t the only option out there. Fiber is generally faster than cable, especially in upload speeds, but it involves added cost for companies because it requires new cables and network architecture. That installation cost is at least partially why Google Fiber dialed back plans for its broadband rollout.

The competition

You have a ton of choices in DOCSIS 3.0 cable modems, and each ISP has its own list of compatible models. We like the Netgear CM500 because it’s reliable and it’s widely compatible across ISPs. If you plan on staying with the same ISP and in the same speed tier for a while, you might be able to save a little money by buying a less-flexible alternative. Either way, always check your ISP’s compatibility list before making a purchase.

We reached out to Intel, Arris, and Netgear to investigate, and learned that Intel has released a firmware update to modem makers. Arris is currently rolling out the fix to ISPs, and Netgear has acknowledged the issue as a security vulnerability but hasn’t yet announced a fix. Both the SB6190 and the CM700 have sizable pools of positive owner reviews, but if you’re still concerned, rent a modem from your ISP (so the ISP is liable and will replace it if anything goes wrong) until the firmware rollout is complete.

Our previous pick, the Arris SURFboard SB6183, is still a great modem and a terrific option if your ISP supports it. But the SB6183 doesn’t have as widespread support as it used to, especially compared with our current picks. We’ve also seen some reports of overheating issues with the SB6183. When we reached out to Arris about the issue, a representative replied via email, “ARRIS devices are fully tested to meet the stringent UL (Underwriters Laboratory) requirements as well as our own heat and safety requirements. For example, our SURFboard SB6183 modem is designed to operate in an ambient temperature range of 32F to 104F (0C to 40C) and continues to perform well in rigorous testing.” That said, don’t store your modem in an enclosed space or somewhere that blocks the vents. If you do have the SB6183 and are experiencing issues with overheating, you can contact Arris customer service.

In the chart below, we list which of our cable modem contenders work with which ISPs based on information from each ISP. (Optimum doesn’t provide a list of compatible modems.) Where applicable, we also include the maximum speeds each ISP supports. We didn’t include modem/router combos, because we don’t recommend them.

*Suddenlink told us that all DOCSIS 3.0 modems will work with the company’s service, though Suddenlink doesn’t list the models specifically. Call Suddenlink to verify compatibility before purchasing.

Footnotes:

1. Sometimes, you can track down user-reported information about channel availability, such as in this DSLReports forum thread with Comcast channel information, but otherwise you’re stuck trying to figure it out for yourself by combing through forums or asking a service representative.Jump back.

Thorin Klosowski is a staff writer for The Wirecutter. Prior to that,
he spent several years at Lifehacker as the resident Apple and Raspberry Pi
guide writer. If he’s not hurriedly attempting to fix some piece of tech
he just broke, he’s probably on a bicycle hunting down doughnuts somewhere in Los Angeles.

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